扩表空大小，需要考虑系统文件大小的限制吗？
Centos7 下的ifconfig和netstat命令
Centos6换过来后感觉到不少细微的变化,CentOS 7默认没有ifconfig和netstat两个命令.
ifconfig其实使用ip addr命令可以代替，在cenots6下的ss命令可以代替netstat，但是现在的ss和以前的完全是两样 ，还是得装上才行方便查看端口占用和tcp链接攻击等等。
把net-tools包装上就好了
yum install net-tools
如下：
[root@chefclient ~]# yum install net-tools
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: mirrors.tuna.tsinghua.edu.cn
* extras: mirrors.tuna.tsinghua.edu.cn
* updates: centos.ustc.edu.cn
Resolving Dependencies
--> Running transaction check
---> Package net-tools.x86_64 0:2.0-0.17.20131004git.el7 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
=============================================================================================================================================================
Package Arch Version Repository Size
=============================================================================================================================================================
Installing:
net-tools x86_64 2.0-0.17.20131004git.el7 base 304 k
Transaction Summary
=============================================================================================================================================================
Install 1 Package
Total download size: 304 k
Installed size: 917 k
Is this ok [y/d/N]: Y
Downloading packages:
net-tools-2.0-0.17.20131004git.el7.x86_64.rpm | 304 kB 00:00:00
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : net-tools-2.0-0.17.20131004git.el7.x86_64 1/1
Verifying : net-tools-2.0-0.17.20131004git.el7.x86_64 1/1
Installed:
net-tools.x86_64 0:2.0-0.17.20131004git.el7
Complete!
[root@chefclient ~]#
[root@chefclient ~]# netstat -antp
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 831/sshd
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 1948/master
tcp 0 0 192.168.122.136:47321 166.111.206.63:80 TIME_WAIT -
tcp 0 0 192.168.122.136:55083 202.118.1.64:80 TIME_WAIT -
tcp 0 0 192.168.122.136:22 192.168.122.1:45917 ESTABLISHED 8798/sshd: root@pts
tcp6 0 0 :::80 :::* LISTEN 832/httpd
tcp6 0 0 :::22 :::* LISTEN 831/sshd
tcp6 0 0 ::1:25 :::* LISTEN 1948/master
[root@chefclient ~]#